The use of ink-jet printers and the formulation of special inks for printing on paper or similar materials have been the subject of intensive investigation for several years. Dyes have frequently provided the coloring components in such inks. Since these inks usually are waterbased, water-soluble dyes have been used; these dyes are azo, anthraquinone, methine, xanthine, oxazine, thiazine, etc. The water solubility has been provided by sulfonic acid groups or their salts attached to one or more aryl components of the dyes. Sulfonic acid groups, however, have near-zero resonance and near-zero inductive interaction when bound to aromatic rings; also, they cause a slight loss of color intensity due to steric interactions with an azo group when located adjacent the azo group. Furthermore, the sulfonate group contributes to solubility but not to waterfastness For these reasons, the search for other dyes which can be used in ink-jet printers has continued.